Tuesday, February 07, 2012

Skydiving from Space

Felix Baumgartner epitomizes thrill-seeking. The 41-year-old Austrian skydiver already has a history of impressive feats: He has crossed the English Channel in freefall, BASE jumped from the Christ the Redeemer statue in Brazil, and BASE jumped from the Petronas Towers in Malaysia. Now he plans to raise the stakes.

One of Baumgartner's test flights. Image Credit: Red Bull

Through a partnership with Red Bull, Baumgartner plans to jump from a weather balloon 120,000 feet above the Earth at the edge of space, breaking the sound barrier while plummeting toward Earth. In the process, he'll shatter records for the highest jump and the fastest speed during a freefall descent. Baumgartner plans to jump in August now that his legal team has resolved legal issues surrounding the project.

But there's more to the mission than pure adrenaline. In the video below, Baumgartner and his team of scientists and engineers explain how they hope to obtain valuable data about human spaceflight.

Video Credit: Red Bull

One notable member of the mission team is Joseph Kittinger, the current record holder for the highest parachute jump. In 1960, Kittinger rode aboard a gondola lifted by a helium balloon to an altitude exceeding 100,000 feet. He then jumped from the gondola, reaching speeds around 640 miles per hour.

For his flight, Baumgartner will travel about 20,000 feet higher and travel over 100 mph faster, breaking the sound barrier. To withstand the extreme cold, low pressure and tremendous forces involved with the feat, Baumgartner will be outfitted with a special pressurized suit.

Without the suit, the low pressure environment at the edge of space would be unbearable. When outside pressure is too low, gas bubbles form inside the body, causing extreme swelling, oxygen loss, and hemorrhaging of the lungs.

When Kittinger completed his jump over 50 years ago, his pressurized glove malfunctioned, and his hand swelled to twice its normal size. By testing these pressurized suits at high altitudes, researchers hope to better understand the risks of human spaceflight and how to avoid them.

In addition to low pressure, Baumgartner will face extreme acceleration — he will break the sound barrier within 35 seconds of jumping from his capsule. Large forces accompany rapid accelerations, so Baumgartner's suit has been meticulously designed by his team to withstand these forces.

As Baumgartner prepares for his jump, you can check out this page from Red Bull for updates, videos, and images.

8 comments:

  1. Hardly extreme acceleration.

    I daresay it will be no more than 1 G
    all of the way down until either impact
    or the parachute opening,

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  2. I was about the comment the same thing nsomos.

    You can only get one G out of one G. Furthermore, there are no forces involved during freefall due to the acceleration of gravity, remember Einstein's elevator. The forces are due to the speed of the molecules flying by as the acceleration creates velocity differential between the air and the person falling.

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  3. The drag due to air might cause him to decelerate (i.e. accelerate in the opposite direction of his velocity) at more than 1 G, until he slows to terminal velocity, at which point his acceleration will be zero.

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  4. Nsomos and Curtis: You're both correct that the downward acceleration would not exceed 1 G during the freefall; I admit that I didn't make that clear in my post.

    On the other hand, as Buzz stated, the deceleration as the skydiver reenters the lower atmosphere may exceed 1 G due to air resistance.

    Also, if the skydiver enters an uncontrolled spin, the forces at the extremities can get very high. During one of Kittinger's first jumps in 1959, he lost consciousness after his small parachute deployed incorrectly, causing him to spin at 120 RPMs.

    More information: http://www.nmspacemuseum.org/halloffame/detail.php?id=99

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  5. Not a physics guy here, help me out. So he accelerates to past the speed of sound. Does he then slow down before deploying the parachute? Because to me if you open a parachute when you are going that fast you are going to break every bone in your body.

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  6. Tom: The team plans to have him accelerate past the speed of sound when he gets down to around 100,000 feet above ground. After this point, he'll start encountering more and more air resistance as he approaches the ground, slowing him down.

    He won't deploy his parachute until he's about 5000 feet above ground. By this time, he should have slowed down enough so that deploying his parachute won't be harmful.

    Red Bull has a nice infographic that explains the mission visually: http://www.redbull.com/cs/Satellite/en_INT/Article/Red-Bull-Stratos--Felix-Baumgartner-ready-to-021243159070520

    Just scroll to the bottom of that page.

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  7. The drag force F is proportional to v^2 which will cause considerable acceleration=F/m.

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  8. Regarding his starting altitude; it is not even near space. The official boundary altitude between the athmosphere and space, called the Kármán line, is at 100 km (62 mi) i.e. 2.5 times higher.

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